Process of forming wheel hubcaps



Se t, 26, 1944,

G. A. LYON PROCESS OF FORMING WHEEL HUB CAPS Filed March 26, 1940 3'Sheets-Sheet l 65019645 /7LsE/Er 4mm.

G. A. LYON PROCESS OF FORMING WHEEL HUB CAPS Sept. 26, 1944.

Filed March 28, 1940 v 3 Sheets-Sheet IKE-Z Z 6:042 05 flmser ire/v.

Patented Sept. 26, 1944 Gimme.

This invention relates to an automobile wheel construction and, moreparticularly, to the method of making a hub cap forming a portion ofsuch a construction. in particular, this invention relates to a processof making hub caps of the type shown in my copending application en=til-ed Wheel cover member and method oi malt-=- ing same" filed February20, 1939, Serial. No. 257,425. a

An object of this invention is to provide an improved and simplifiedmethod of melting a cover member or hub cap for an automobile wheel.

Another object of this invention is to provide a method of making anautomobile wheel hub cap of the type specified with less waste of metalthan has been involved in the process hitherto known.

Another object of this invention is to provide a method of making anautomobile wheel hub cap of the type specified in fewer operations thanin the processes hitherto known. 1

Another object of this invention is to provide a method of forming anautomobile wheel hub cap and a wheel cover disk from a single circularblank of metal.

In accordance with the general features of this invention, the blank, orthe portion of the blank, for forming the hub cap is first drawn, by oneor more operations, into an intermediate form having a crown portionsurrounded by a cylindrical wall. drical wall is then trimmed toeliminate any irregularities produced by the drawing operation andcurled to form a beaded edge. The final operation consists in bulgingout the portion of the cylindrical wall next to the crown portion togive the hub cap its final shape. During this last operation, the beadededge is positively prevented, by suitable dies, from being drawn into anirregular shape so that no additional straightening or trimmingoperations are necessary.

In previous processes of making hub caps of the type to which thisinvention relates, it has been the practice to perform the bulging-outoperation before curling the edge of the metal and without preventingthe formation of irregularities in the edge of the metal. It hastherefore been necessary to perform a second trimming operation afterthe bulging-out operation and before the curling of the edge of themetal into a bead.

Other objects and features of this invention will more fully appear fromthe following description, taken in connection with the accompanyingdrawings which illustrate the preferred manner iii) The free edge of thecylinof carrying out the invention, together with some modificationsthereof, and in which:

Figure l is apartial vertical cross sectional view taken through a wheelconstruction embodylng a hub cap and a wheel dish produced in accordancewith my invention;

Figure 2 is a front view, on a reducedscale, of the wheel constructionshown in Figure 1;

Figure 3 is a cross sectional view illustrating one of the first stepsin the process of forming the wheel disk cover and hub cap shown inFigwas i and 2;

Figure 4 is a cross sectional view illustrating a lurther step in theformation of the wheel disk cover shown in Figures 1 and 2;

Figures 5, 6, '7, 8, and 9 are cross sectional views showing furthersuccessive steps in the formation of the hub cap shown in Figures 1 and2, some of these views also illustrating the apparatus employed inperforming these steps;

Figure 19 is a cross sectional view similar to Figure 5 showing a.modified form of apparatus for performing the steps illustrated inFigure 5;

and

Figure 11 is a. cross sectional view through a die set and blank forcarrying out the first step in the formation of the hub cap when it isdesired to make a hub cap without simultaneously making a wheel coverdisk.

As shown on the drawings:

The reference character 10 designates generally a conventional dropcenter tire rim, including the usual side flanges H and a base flange 2,to which is riveted, welded, or otherwise secured, a spider or bodymember l3 which has a central depression or bolt access opening I4,defined by a lateral wall I5 terminating in a bolt flange It. This boltflange I6 is adapted to be secured in the usual way, such as by capscrews or bolts, to a suitable circular support or hub of v theautomobile.

As is well known to those skilled in the automobile wheel art, it iscommon practice to provide a. detachable closure member for concealingthese bolts. A closure or cap member constructed in accordance with thefeatures of this invention is shown in Figures 1 and 2 and is designatedgenerally by the reference character 20. The closure member, as I shalldescribe more in detail hereinafter, is adapted to have a snap-oncoaction with a plurality of lateral projections or bumps IS on the wallH of the wheel body part l3. These projections may, if it is so desired,be attached to this body part, although the preferable way of providingthem is to depress spaced portions of the body part at the time that thebody or spider part is being fabricated.

Each of these projections I8 is of relatively narrow width and of apredetermined height for ooaction with a flexible skirt 2i on the hubcap or cover member 2t. While any suitable number of projections may beused, I have found that satis-- sion of the rear edge oi the cap,particularly when this edge is sprung into hub cap retaining cooperationwith the spaced projections N.

The dome portion 22 of the hub cap is resilientto the extent that it islike a spring in that it is capable of resisting impact blows and.moreover, will enable slight indentations therein to be snapped orpressed outwardly by manual pressure on the inner side of theindentation.

The skirt 2|, by reason of its extending in a generally axial directionhas its greatest flexibility at its inner edge 25. Moreover, when thisskirt is in a sprung condition on the wheel, it does not materiallyaffect the remaining portions of the hub cap by reason of the fact thatit emanates from a shoulder 23 on the cap which is held and seatedtightly against an outer face of the wall of body part IS.

The shoulder 23 is between the flexible dome and flexible skirt and byreason of its being located at the turned and channeled section or themargin of the cap is relatively rigid so that it can withstand withoutdistortion or buckling the pressure of a pry-oil tool inserted betweenthe edge of this shoulder and the adjoining wheel body. In theapplication of the hub cap to the wheel, it is first brought to aposition in which the bead 25 rests against the protuberances It atpoints spaced axially outwardly of the final point of contact betweenthe bead 25 and the protuberances it. The hub cap is then forced bodilyaxially inwardly and snapped into place, the portions of the bead 25 incontact with the protuberances l9 and the adjacent portions oi'the skirt2! of the hub cap are deflected radially inwardly during this operation,while the intermediate portions of the bead 25 and skirt 2| springradially outwardly. In its final position,

- shown in Figure l, the bead 25 and the skirt 2| of the hub cap are inthe above described flexed position, thereby tightly and flexiblybinding the edge under tension to the body part 0! the wheel so as todetachably retain the hub cap on the wheel. This coaction is of such amagnitude that it requires the use of a pry-oil tool, such as a screwdriver, as well as considerable pressure, to remove the cap from thewheel; this removal being eflfected by inserting the edge of the screwdriver between the relatively rigid lateral shoulder 23 of the cap andthe wheel body member i 3, and prying the cap outwardly.

The wheel construction, as illustrated in Figure 1, is also providedwith a wheel cover disk 21 having an inner part 28 overlying the wheelbody I3 and an outer part 28 overlying a portion asoaoes tained inplace'on the wheel by its axially innor edge which fits in under and issecured by the turned-under margin 23 of the hub cap 20. If desired, thewheel cover disk 21 may also be held in place by a frictional engagement01 its outer marginal'edge 30 with the axially inner surface of the sideflange II or the rim Hi.

In Figures 3 to 8 of the drawings, I have illustrated a novel method ofmaking the hub cap til and the wheel cover disk 21 illustrahd in Figures1 and 2, which method provides a very economical manufacturing process.More particularly, both the hub cap 20 and the wheel cover disk 21 areblanked from a single piece of thin sheet metal stock 32. The first stepin the process of forming the hub cap 20 and the wheel cover disk atcomprises taking a circular blank of suitable size and drawing it, byone or more operations, into the shape shown in cross section in Figure3. It will be noted that this shape comprises a central rounded crownportion 33 joined by a cylindrical wall portion 34 to a wide rim or diskportion 35. The wall portion 34 has the same diameter as the skirtportion 2| ofthe finished hub cap, and the outer rim or disk portion 35has approximately the same outside diameter and the same generalconfiguration as the finished wheel cover disk 21.

After the blank 32 has been formed to the shape shown in Figure 3, it isdivided into two parts by being out along a circle whose position isindicated in Figure 3 by the the lines 86. The diameter of this circleis the same as the inside diameter of the finished wheel cover disk 21,andv the wheel cover disk 21 is completely formed by shaping the severeddisk portion to the final form shown in Figure 4;.

The central portion of the partially formed blank shown in Figure 3,this central portion comprising the crown It, the cylindrical wall 24,and the radially inner part 01' the disk 35 lying between the lines 38,is subjected to furof the rim [0. The wheel cover disk 2! is retheroperations and finally forms the finished hub cap 2. If it is desired toproduce a hub cap 20 without producing a wheel cover disk 21, a circularsheet metal blank 31, considerably smaller than the blank 32 may beemployed in making a partially formed hub cap similar to the centralportion or the partially formed hub cap and wheel cover disk shown inFigure 3. In carrying out this alternative procedure. the blank 31, asshown in Figure 11, is placed in a suitable die set comprising a die 38,a punch 39, and a blank holder 40 connected to the punch by suitablesprings 4|. The die 38 is formed with a central recess 42 into which thepunch 39 is adapted to draw the blank 31, and the die It and the blankholder 40 are provided with a circular tongue 43 and groove 44concentric with the recess 42 01' the die. The tongue 43 and groove 44provide a tortuous passage through which the edge of the blank 31 isdrawn. This serves to more eil'ectually hold the edge of the blank 31and also to cold work, to an additional extent, that portion of theblank being drawn through the tortuous passage and to thereby enhenceits physical properties. When the stroke of the punch 39 is completed,the blank 31 has been drawn to the shape indicated by the dotted line31' and. has substantially the same shape as the portion of the membershown in Figure 3 and lying between the lines 38.

The partially formed hub cap, made by either of the steps describedabove, is then subjected to a further drawing operation, as illustratedin Figure 5. Figure shows a portion of a die set go erally similar tothe die set shown in Figure 11 in that it comprises a die 46 having acentral circular opening 41, a punch 48, and an annular blank holder 49fitting around the punch 48 above the die 46. Since both side of the dieset are alike, one side only is illustrated in Figure 5. The principaldifierences between the die set illustrated in Figure 5 and the die setillustrated in Figure 11 are that, in the former die set, the aperture4?! in the die 46 extends clear through the die so that the piece beingworked upon can be discharged through the opening, and in that the blankholder it) is provided with a lip 50 which is adapted to extend downinto the die it inside of the cylindrical wall 34 of the blank beingworked upon. It will b noted that the blank is formed with a filletportion 45 between the cylindrical wall portion 3 and the relativelyflat rim portion 35 and that the fillet 35 i securely held, both on theoutside and the inside, by the die it and the lip 56 of the blank holderiii.

The operation which is performed in the die 6 set illustrated in Figure5 consists of drawing all of the metal in the fillet and in the flangeinto an extension of the cylindrical wall i l, the metal being guidedthroughout its entire movement into the cylindrical well formed by meansor the die it and the blank holder at. The movement of the metal is, ofcourse, caused by th downward movement of the punch it in theconventional manner.

After the operation performed in the die set shown in Figure 5 has beencompleted, the blank has the shape shown in cros section in Figure 6 andconsists entirely or a crown portion 35 and a cylindrical wall portion5%. The next operation is to trim the edge of the wall portion to toexactly the proper length by making a cut 5i at the proper place. Thecut 5i removes a small strip of waster)? from the rim of the cylindricalportion 35 and eliminates any variation in length or irregularities inthe edge of the work piece 33-3 3.

The next step in th formation of the hub cap, is the curlin of the edgeof the cylindrical wall portion 34 to form a bead 22, This operation iscarried out with a curling punch and die 54 having the configurationshown in Figure 7. The edge of the cylindrical wall portion 34 i forcedby the die 53 into an annular round-bottomed groove or trough 55 in thedie 54 and is thereby forced to curl around and form itself into thebead 22.

The next operation in the forming of the hub cap consists of bulging outthe portion of the cylindrical wall 34 adjacent the crown portion 33 inorder to form th edge portion of the dome 22 and the turned-under margin23 of the finished hub cap shown in Figure 1. This operation isperformed by the die set illustrated in Figures 8 and 9. This die setcom-prises an upper die member 55 whose under surface i formed with around hollow 56 having the shape of the dome portion 22 of the finishedhub cap, a central lower die member 51 having its upper end shaped andpositioned to hold the center 01 the crown portion 33 of the partiallycompleted hub cap against the center of the hollow 56 in the upper diemember, a plurality of outer lower die members 58 which together form aring adapted to fit around the cylindrical wall portion 34 of thepartially formed hub cap, a rubber expander 59 in the form of a ringfitting around the upperpar't of the central lower die member 51 andshaped to fit against the outer part of the crown portion 36 and theupper part of the wall portion 34 or the partially completed hub cap,and an annular compressor 60 fitting between the central and outer lowerdie members 57 and 58 immediately below the rubber expander 58. It willbe noted that the outer lower die members 58 are formed with an undercutti on their inner surfaces, this undercut accommodating the bead 22 andterminating in a shoulder 62 near the'top. When the partially formed hubcap 33-3t-22 i placed in the dies, the head 22 on its lower edge liessome distance below the shoulder 82 on the outer lower die members, asshown in Figure 8.

The die set shown in Figures 8 and 9 is op erated by forcing the upperdie member 55, the central lower die member 5i and the outer lower diemembers 58 downwardly with respect to the compressor 6i]. This forcesthe rubber expander it down onto the compressor ill and, since rubber ispractically incompressible volumetrically, causes the expander 59 tobulge out laterally as shown in Figure 9. This bulging forces the upperportion of the cylindrical wall t l out into the peripheral portion ofthe hollow it in the upper die member 55 and draws the head 22 upagainst the shoulder 32 on the outer lower die members at. The pressureapplied is sufiicient to pull the bead 22 up tightly against theshoulder around its entire circumference. If any portion or the head 22should pull up against the shoulder t2 before any other portion, thatfirst portion is stopped and prevented from pulling up ruither by theshoulder 52 until the other portions are pulled up into line. Thus thebead it is formed into a perfect circle irrespective of any smallirregularities that may occur during the drawing operation. Thiscompletes the formation of the hub cap it, with the exception, ofcourse, of such operations a polishin and embossing or paintingornamental or identifying features.

An alternative set of dies 54-t5-65, shown in Figure 10, may be employedfor carrying out the steps performed by the dies shown in Figure 5. Thisalternative set of dies comprises an annular lower die member 64, apunch 65, and an annular blank holder 66 adapted to fit around the punchand on top of the die 64. The die set 64-45-66 is generally imilar tothe die set shown in Figure 5, but the lip 61 on the lower inner cornerof the blank holder 66 is considerably thinner than the correspondinglip 50 on the other die set. This allows the side or the punch 65 to bemade straight andof a constant diameter instead of having the upperportion of reduced diameter, as is the case with the punch 48 in the dieset shown in Figure 5.

From th foregoing, it will be seen that I-have provided a method ofproducing hub caps and wheel cover disks or of producing hub caps alonewhich involves less waste of material and fewer operations thanpreviously known methods of producing these articles. It will thereforebe apparent that my invention brings about a substantial reduction inthe manufacturing cost of these articles. While I have disclosed onlyone principal way of carrying out the invention and two modificationsthereof, it will, of course, be understood that I do not wish to belimited thereto, since many modifications may be made, and I, therefore,contemplate by the appended claims to cover all such modifications asfall within the true spirit and scope of my invention.

I claim as my invention:

1. The method of making a round sheet metal object having a bulged outportion and a rim,

said bulged out portion being of greater diameter than the rim, whichcomprises drawing a flat blank of sheet metal into an intermediate shapehaving a crown portion and a cylindrical wall portion with across-section similar in size and shape to the rim of the finishedobject and having an outwardly extending flange connected to saidcylindrical wall portion by a fillet, drawing the metal in said flangeand said fillet into an addition to said cylindrical wall portion whileedge toward said crown portion during the bulg-i ing out operation, andpositively stopping the movement of said edge toward said crown portionduring the last steps said bulging out operation at a predetermineduniform distance from said crown portion to remove any undulationsdeveloped in the edge as said portion 0! the cylindrical wall is bulgedout and as said remaining portion is drawn toward the crowned portion.

' 2. The method of making a round sheet metal object having a bulged outportion and a rim, the bulged portion being of greater diameter than therim, which comprises working a sheet metal blank into an intermediateshape, said intermediate shape having a crown portion and a cylindricalwall portion merging into said crown portion at one end and terminatingin an edge of predetermined definite shape at the other end, bulging outa portion of said cylindrical wall adjacent said crown while holding theremaining portion of said cylindrical wall against deformation anddrawing said remaining portion and said edge towards said crown portionduring the bulging out operation, and positively stopping the movementof said edge towards said crown portion at a predetermined line.

3. The method of making a round sheet metal object having a bulged outportion and a rim, the bulged out portion be ing of greater diameterthan the rim, which comprises working a sheet,

metal blank into an intermediate shape, said intermediate shape having acrown portion and a cylindrical wall portion merging into said crownportion at one end and terminating in an exactly circular edge at theother end, bulging out a portion oi said cylindrical wall adiacent saidcrown while holding the remaining portionoi said cylindrical wallagainst deforma- .tion and drawing said remaining portion and said edgetowards said crown portion during the bulging out operation, andpositively stopping the movement of said edge towards said crown at apredetermined uniformdistance from said crown.

4. The method oi making a round sheet metal object having a bulged outportion and a rim, the bulged out portion being of greater diameter thanthe rim, which comprises working a sheet metal blank into anintermediate shape, said intermediate shape having a crown portion and acylindrical wall portion merging into said crown portion at one end andterminating in an edge oi predetermined definite shape at the other end,bulging out a portion 0! said cylindrical wall adjacent said crown whileholding the remaining portion or said cylindrical wall againstdeformation in a direction perpendicular to said wall and drawing saidremaining portion and said edge towards said crown portion during thebulging out operatiomand positively stopping the movement 0! said edgetowards said crown portion at a predetermined line while continuing toapply a'bulging out force to said first portion of said originallycylindrical wall.

5. The method of making a round sheet metal object having a beaded rimand a bulged out portion of greater diameter than said rim, whichcomprises working a sheet metal blank into an intermediate shape, saidintermediate shape having a crown portion and a cylindrical'wall portionmerging into said crown portion at one end and terminating in a freeedge, trimming said free edge at a predetermined uniform distance fromsaid crown portion, curling said edge to form a bead, bulging out aportion oi said cylindrical wall adjacent said crown while holding theremaining portion or said cylindrical wall and said bead againstdeformation in a direotion perpendicular to said wall and drawing saidremaining portion and said bead towards said crown portion during thebulging operation, and positively stopping the movement of said headtowards said crown portion at a predetermined uniform distance from saidcrown portion and before the bulging operation is completed.

